Cup plug expander



F. E. DUDLEY April 30, 1968 CUP PLUG EXPANDER 2 Sheets-Sheet 1 Filed May 20, 1966 INVENTOR FRANK E DUDLEY April 30, 1968 F. E. DUDLEY 3,380,276

CUP PLUG EXPANDER Filed May 20, 1966 2 Sheets-Sheet 2 INVENTOR FRANK E. DUDLEY United States Patent 3,380,276 CUP PLUG EXPANDER Frank E. Dudley, 12 Center St., Westmont, NJ. 08108 Filed May 20, 1966, Ser. No. 551,668 8 Claims. (Cl. 72122) This invention relates generally to metal expanding devices and more particularly to an expander for use with a cup-shaped metal plug.

Although the invention is not specifically ilimited to the use of the present device for so-called freeze plugs or cup plugs in engine blocks, the description will be directed to such a device for purposes of explanation.

In past years, cooling systems for automobiles have been provided by placing water in the jacket of the automobile engine and connecting the same to a radiator filled with water. Overflow pipes in the radiator permitted water to flow to atmosphere when the engine became heated. To provide openings inside the engine block for the coolant, it was common practice to utilize sand cores to create voids within the block during casting. After casting, the sand cores were removed by forcing water through the holes in the cylinder block thereby removing the sand cores. It was then necessary to close these holes through which the sand cores were removed by driving freeze plugs or cup plugs into the openings. Originally,'the only pressure within the cooling system was the head of water in the radiator against such cup plugs.

However, in later years as the automobile engine developed, cooling systems which operate under sixteen or seventeen pounds pressure have come into being and this pressure has resulted in considerable difficulties created by leaks around the cup plugs which are merely driven or pushed into place in the core holes.

Accordingly, it is an object of this invention to provide a tool whereby the cup plug wall may be expanded tightly against the engine block so as to withstand any of the operating pressures within the coolant system.

Another object of this invention is to provide an expanding tool for use with any type of cup-shaped device wherein the walls of the device must be expanded to fit within any aperture.

Basically, the device of the present invention comprises a substantially cylindrical base having opposed parallel faces with an aperture axially therethrough The base has a radius less than the walls of the cup to be explained A plurality of cylindrical rollers are rotatably mounted about the outer portion of one of the faces of the base and these rollers are free not only to rotate, but'to slide across the base a predetermined distance in any direction. When a tapered mandrel is inserted from the opposite side of the base, it engages the rollers on the inside thereof and, as the mandrel is rotated in one direction and forced into the opening to a point against the freeze plug, the rollers rotate about the inner wall of the plug and are pressed outwardly so as to expand the wall outwardly against the particular opening with which it is associated.

The above objects of this invention as well as further uses will be clearly understood from the following description when taken in conjunction with the drawings wherein:

FIG. 1 is a cross-sectional view of a plug placed within an engine block;

FiG. 2 is a cross-sectional view similar to FIG. 1 and additionally showing the device of the present invention within the cup plug;

FIG. 3 is a perspective view of the expander of the present invention;

FIG. 4 is a sectional view taken along the lines 44 of FIG. 2;

FIG. 5 is a plan view of the base element of the present invention with the rollers removed; and

3,380,276 Patented Apr. 30, 1968 FIGS. 6 and 7 are fragmentary sectional views showing the movement of the rollers along the face of the base element. 7 7

FIG. 1 illustrates a section 11 of an element such as an engine block having opening 13 therein which is closed by means of a cup plug 15 having a circumferential wall 17 thereabout.

Turning now to FIGS. 2 and 3, there is shown a substantially circular base 19 having opposed parallel faces 21 and 23. A plurality of inclined planes 25, 27, 29 and 31 may be cut into one face of the base 23 as is more clearly shown in FIG. 5. The inclined planes are substantially equally spaced about the outer periphery of the face 21 and terminate in shoulders 33, 35, 37 and 39 which extend upwardly to the face 21 substantially perpendicular thereto.

Rollers 51, 53, 55 and 57 are rotatably mounted to each of the respective faces by any means such as bolt members 61, 63, 65 and 67, respectively, which may be secured in the desired position by means such as nuts 71 and 75 as shown in FIG. 2. The bolt members pass through drill holes 43, 45, 47 and 49.

As shown in FIGS. 6 and 7, the opening 52 in the base of the roller is substantially larger than the shaft diameter of the bolt 61. Therefore, the roller may slide across the face of the inclined plane in any direction by an amount predetermined by the size of the opening 52, for purposes which will become apparent as the description proceeds. A mandrel 77, which may be tapered, is then driven upwardly into the aperture 41 and at the same time rotated.

FIG. 4 illustrates the effect or this axial and rotational movement of the mandrel. As it is driven upwardly toward the cup itself, it forces each of the rollers outwardly. Addition-ally, the plane on which each roller rests inclines upwardly in the same direction as the rotation of the mandrel 77. The ultimate effect of the axial and rotational movement of the mandrel 77 causes each roller to ride upwardly on the inclined plane and rotate so as to move about the inner wall of the cup 15. Accordingly, the outward pressure and the rotational movement of the rollers causes an equal expansion of the wall of the cup and a firm seating against the wall 13 of the opening in the engine block.

The rollers may also be of a conical shape with the taper of the rollers being in a direction opposite to that of the mandrel so as to provide additional-bearing therebetween. Such a modification is illustrated in FIGS. 6 and 7 which also illustrate the movementiof the roller 81, with 6 showing it in its rest position without the mandrel in place and FIG. 7 showing the effect of the mandrel causing it to ride up the inclined plane. The shoulder 33 terminates the inclined plane and prevents any movement beyond a certain point when the device is not in use. Also, it will be noted that when it is desired to remove the mandrel and the expander itself, the rotation of the mandrel is simply reversed, which causes the rollers to slide back down the inclined plane as the mandrel is rotated outwardly from the expander.

It will now be obvious that the present invention provides a simple and expedient method for expanding cup plugs after they are inserted into the desired opening, with a positive and uniform sealing action which has not, to my knowledge, been heretofore possible. It is to be understood that the above description and drawings are illustrative only and modifications will now be apparent to those familiar in this art. Accordingly, the invention is to be considered as limited only by the scope of the following claims.

I claim:

1. A device for expanding a cup-shaped plug in the wall of an engine block comprising,

a circular base having opposed, substantially parallel faces, said base being of a size to fit within said plug,

a substantially circular aperture through said block, the axis of said aperture being substantially perpendicular to said opposed faces,

a plurality of inclined planes cut in the surface of one of said opposed faces, each of said planes terminat ing in a shoulder substantially perpendicular to said face,

a hollow cylindrical roller on each inclined plane having one end thereof adjacent said associated inclined plane,

means for mounting said rollers to said plane so that they are free to rotate and free to move a predetermined amount both along said inclined planes and laterally thereof for engagement with the walls of said cup-shaped plug,

said rollers having a diameter such as to extend within said aperture and without said circular base, and

rotatable mandrel means for insertion within said aperture and engagement with said rollers so as to rotate said rollers up said inclined plane and outwardly against said walls of said plug.

2. The device of claim 1 wherein said mounting means comprises a threaded member extending into said base.

3. The device of claim 1 wherein said mandrel is tapered so as to force said rollers outwardly from said base as it is inserted within said aperture.

4. A cup plug expander comprising,

a substantially circular base having opposed parallel faces, the diameter of said base being of a dimension such that it fits within said cup,

a substantially circular aperture through said block between said opposed faces,

a plurality of circumferentially spaced inclined planes in one of said faces extending between said aperture and the outer diameter of said base, each of said planes terminating in a shoulder extending between the associated planes and said one of said faces,

a roller rotatably mounted on each of said. planes, said rollers being free to move along said plane and lat- .4 erally thereof a predetermined distance, and rotatable mandrel means adapted to fit with said aperture so as to bear against said rollers and force them into contact with the wall of said cup plug.

5. The expander of claim 4 wherein said mandrel is of a conical shape so as to bear against said rollers in a camming action as it is inserted into said aperture.

6. A device for expanding the walls of a cup plug comprising,

a substantially cylindrical base having opposed parallel faces and an aperture axially therethrough, said base having a radius less than the walls of said cup,

a plurality of cylindrical rollers rotatably mounted about the outer portion of one of said faces, said rollers being free to slide across said one of said faces a predetermined distance in any direction, and

tapered mandrel means for insertion into said aperture from the direction of the other said faces and into rolling contact with said rollers whereby said rollers contact the inner face of the wall of said plug and expand said wall outwardly as said mandrel is inserted into said aperture.

7. The device of claim 6 further comprising an inclined plane in said one face of said base adjacent each of said rollers,

each of said planes inclining upwardly in the directio of rotation of said mandrel and terminating at the lowest point in a vertical shoulder.

8. The device of claim 6 wherein said rollers have a tapered outer surface with the taper being opposite that of said mandrel means. I

References Cited UNITED STATES PATENTS 2,626,581 1/1953 Almgren et al. 113-30 3,047,045 7/1962 Baker 72-1 22 3,221,528 12/1965 Linthicum et al 72122 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Examiner. 

1. A DEVICE FOR EXPANDING A CUP-SHAPED PLUG IN THE WALL OF AN ENGINE BLOCK COMPRISING, A CIRCULAR BASE HAVING OPPOSED, SUBSTANTIALLY PARALLEL FACES, SAID BASE BEING OF A SIZE TO FIT WITHIN SAID PLUG, A SUBSTANTIALLY CIRCULAR APERTURE THROUGH SAID BLOCK, THE AXIS OF SAID APERTURE BEING SUBSTANTIALLY PERPENDICULAR TO SAID OPPOSED FACES, A PLURALITY OF INCLINED PLANES CUT IN THE SURFACE OF ONE OF SAID OPPOSED FACES, EACH OF SAID PLANES TERMINATING IN A SHOULDER SUBSTANTIALLY PERPENDICULAR TO SAID FACE, A HOLLOW CYLINDRICAL ROLLER ON EACH INCLINED PLANE HAVING ONE END THEREOF ADJACENT SAID ASSOCIATED INCLINED PLANE, MEANS FOR MOUNTING SAID ROLLERS TO SAID PLANE SO THAT THEY ARE FREE TO ROTATE AND FREE TO MOVE A PREDETERMINED AMOUNT BOTH ALONG SAID INCLINED PLANES AND LATERALLY THEREOF FOR ENGAGEMENT WITH THE WALLS OF SAID CUP-SHAPED PLUG, SAID ROLLERS HAVING A DIAMETER SUCH AS TO EXTEND WITHIN SAID APERTURE AND WITHOUT SAID CIRCULAR BASE, AND ROTATABLE MANDREL MEANS FOR INSERTION WITHIN SAID APERTURE AND ENGAGEMENT WITH SAID ROLLERS SO AS TO ROTATE SAID ROLLERS UP SAID INCLINED PLANE AND OUTWARDLY AGAINST SAID WALLS OF SAID PLUG. 